Wandering down a suburban street in a modern metropolis, the last thing you expect to see is a medieval castle.

What makes the sight even less likely is that I'm not in Europe or Great Britain, but in North America.

And yet, here it looms, its turrets complete with arrow slits, looking out on a spectacular view over downtown Toronto.

This is Casa Loma, and it must be one of the strangest, most fascinating castles in the world.

Unlike, for instance, Victoria's cheesy Kryal Castle, which was built as a tourist attraction, Casa Loma was created as a home for one of Canada's richest men.

Only through the misfortune of its owner did the castle become an attraction open to the public in Canada's largest city.

Henry Pellatt, a wealthy industrialist and Anglophile, made his initial fortune through early investment in electricity supply and railroads.

His travels in Europe inspired a love of fine art and architecture, which in turn inspired him to build his giant home.

In 1911, worth C$17 million ($20.69 million) at the time, Pellatt set to work building Casa Loma with architect E.J. Lennox, incorporating classic castle features such as battlements and even secret passageways.

It took three years and C$3.5 million to build - a fortune now, an outrageous fortune then.

Seeing Casa Loma as it stands today, still in perfect condition, is a strange experience. The castle sits on Avenue Road Hill and is invisible as I approach from the train station at the bottom of the hill.

It's only when I reach the top of the stairs leading up the hill (which seem to be very popular with joggers) that the castle becomes visible. It sits there, in a fairly typical, tree-lined suburban street, a large part of its grounds now converted into parking spaces.

I enter through the large doors to the great hall, with its ceiling 18 metres high, and pick up an audio guide. This is a must, as guests wander the building on their own, and the audio guide adds plenty of fascinating details to the experience.

It's these details, and the general weirdness and folly of such a place in a Canadian city, that makes visiting Casa Loma worthwhile.

I take my time wandering through each room, from the great hall and dining room, to the beautiful and bright conservatory, through Pellat and his wife's separate bedrooms, even into the servants' quarters and to the top of one of the turrets.

Of course, I can't miss the opportunity to take the tunnel that leads to the stables, passing under what is now quite a busy thoroughfare.

Pellatt was forced to build the tunnel after the City of Toronto decided to put a road through his grounds. It was just one of a great many battles Pellatt had with the city's officials - many of whom, it seemed, despised the ostentatious lifestyle and home of the man. Unfortunately for Pellatt, the city tended to win.

The greatest, and perhaps saddest, victory for the officials was Pellatt's loss of Casa Loma in order to avoid bankruptcy - having lost his local monopoly on electricity supply and having suffered a series of bad investments,